Japanese non-examined Patent Application Publication No. 2008-307655 discloses a power tool having a dynamic vibration reducer as vibration suppression device which alleviates vibration generated when the power tool is working. The power tool described in No. 2008-307655, has a crank mechanism which is actuated by a motor and actuates a hammering mechanism. In addition a second crank mechanism is disposed at one side of the crank mechanism opposed to the motor. The second crank mechanism actuates a weight of the dynamic vibration reducer aggressively. Namely vibration generated during an operation is decreased by forcibly actuating the dynamic vibration reducer.
However, because the crank mechanism for hammering the tool bit and the second crank mechanism for actuating the dynamic vibration reducer are disposed to be aligned with each other in an axial direction, a construction of the power tool is complicated and irrational for the purpose of weight saving of the power tool.